Multi-Protocol Label Switching (MPLS) belongs to the 3rd generation network architecture, and is a new generation Internet Protocol (IP) high-speed backbone network exchange standard. A basic constituent unit of an MPLS network is a label switching router (LSR), and a forwarding path of an MPLS message in the MPLS network is a label switched path (LSP), and the working process of the network is as the following. At an ingress LSR, packets with the same forwarding and processing mode are classified into a forwarding equivalence class (FEC), and an identifier is added for each packet to form a labeled packet, and the label is used for uniquely identifying an FEC to which a packet belongs. The ingress LSR forwards the labeled packet to a next hop on the LSP according to the label on the packet and a preset label forwarding table, at each subsequent hop, an output port of the next hop and a new label are pointed out by using the label as a pointer without analyzing the packet header, and the labeled packet is forwarded through a designated output port after replacing the old label with a new label. At an egress LSR, the label in the packet is removed, and the packet is then forwarded according to a route table.
In order to determine whether an LSP can correctly forward data, the MPLS Ping technology may be adopted for detection, that is, an echo request message is sent from an ingress LSR, and is forwarded by the LSP and reaches an egress, and then an echo reply message is returned by an egress LSR, and if the ingress LSR receives the echo reply message, the LSP can be used for data forwarding. In order to obtain the information of each node at the ingress node, the MPLS TraceRoute technology may be adopted, that is, echo request messages with time to live (TTL) of 1 to a certain value are continuously sent on the LSP, so that each node on the LSP returns an echo reply message when receiving an echo request message with expired TTL, and carries information of the node in the echo reply message, and therefore the ingress node may collect the information of each node on the LSP.
According to the link aggregation group (LAG) technology, multiple physical links between two adjacent devices are used as a logical link, so as to realize link redundancy and load balancing between the two devices, thereby providing a wider bandwidth.
After analyzing the conventional art, the inventors find the following problems.
In conventional art, it cannot be detected that whether an LAG and attribute information of the LAG exist on the LSP, and therefore the difficulty in operation, administration and maintenance (OAM) of the MPLS network is increased. For example, if an LAG exists between two adjacent devices, and three physical links are included therebetween, when one of the physical links fails, and the other two physical links are normal, if an OAM message is transferred to the peer end through the failed physical link in the LAG, the peer end will make a conclusion that a failure occurs to the LAG; however, in fact, the other two physical links on the LAG can still work normally, so the conclusion made by the peer end is not completely correct.